Two-piece ostomy appliance with face-plate bistable coupling ring

Abstract: A two-piece ostomy appliance (10) comprising a pouch component (11) and a faceplate component (12). The faceplate component has disposed thereon a dual-state, bistable coupling ring (20) with a latching member (25) for sealingly engaging the periphery of an opening in the pouch component. The coupling ring has an annular base (21) defining a central opening and a contact face thereon surrounding the central opening. An annular collar (23) extends from the base and a bistable latching member is joined to the collar along an annular hinge line (28), the latching member providing a contact surface and being pivotable about said hinge line. The latching member pivots about the hinge line between a stable, substantially untensioned first state wherein the latching member projects generally axially away from the collar and a stable, tensioned second state wherein the latching member extends in a reverse directon towards the annular base with said contact face of the latching member being positioned for tight engagement with the annular base's contact face or with the annular periphery of the pouch component clamped between the base and the latching member.

Description: The present invention relates to a face plate for a two-piece collection system of the type as described in the preamble of claim 1, and to a two-piece collection system having a face plate of the type as described in the preamble of claim 6. A face plate and a two-piece collection system of this type are described in US-A-4 419 100. This document describes a two-piece collection system, comprising a face plate and a pouch removably attached to one another by a first coupling ring provided on the face plate, and a second coupling ring provided on the pouch. The coupling ring of the face plate has an annular base defining a central opening, an annular collar extending from the base, and a latching member attached to the collar. The latching member is flexible and includes an essentially circumferentially outwardly facing contact surface. The contact surface is adapted to engage a corresponding inwardly facing contact surface of the coupling ring provided on the pouch. When the pouch is to be attached to the face plate, the coupling ring of the pouch is to be shifted over the coupling ring of the face plate thereby bending and/or compressing the latching member radially inwardly towards the opening for providing an elastic fit. For removing the pouch, the two coupling rings must be separated by tearing off the coupling ring of the pouch from the coupling ring of the face plate. When doing so, the latching member will automatically return to its single stable position, ready to receive another pouch. Thus, the coupling ring of the pouch must be sufficiently stiff and strong to compress and to hold compressed, the elastic latching member of the coupling ring of the face plate. US-A-5 167 653 describes two-piece collection system having a face plate and a pouch. Both the face plate and the pouch are provided with coupling rings to be engageable with one another by snap action. Once snapped into another, both rings form a destable hinge. The coupling ring on the pouch is that ring which performs the two stable positions and is formed of a relatively stiff, flexible plastic material. Two-piece ostomy couplings generally require axial compressive forces to secure a pouch ring onto a faceplate ring. Typically, an element of the pouch ring stretches or deforms as it is applied over the faceplate ring bringing such surfaces into leakproof contact. For a more detailed description of further two-piece ostomy appliances, reference may be had to co-owned US-A-4,610,676 and US-A-4,610,677. Recent interest has been shown in providing "flushable" ostomy appliances which are formed of materials, or combinations of materials, capable of dissolving or dispersing when the appliance is discarded into a flush toilet or water closet. Reference may be had to US-A-4,772,279, US-A-4,868,024 and US-A-4,917,689 as illustrative of such flushable ostomy appliances. While the pouches of conventional two-piece systems might seem appropriate candidates for flushable construction, a major disadvantage is that the pouch coupling rings of such two-piece appliances are commonly formed of tough, durable, and semi-rigid polymers such as polyethylene which are incapable of dissolving or dispersing in water and would therefore present a risk of clogging and possibly damaging toilets and sewer systems. Another disadvantage encountered when using a flushable pouch with a two-piece appliance is that a flushable pouch usually has at least one water soluble layer which may have edges exposed to fluids passing through the pouch's stoma-receiving opening and such exposure may result in premature structural failure of the pouch component. The present invention addresses these problems according to claims 1 and 6 by providing a faceplate and a two-piece collection system with a bistable coupling ring which has a latching member. The latching member is provided on the faceplate component such that the latching member releasably engages the edge portion of the pouch's stoma-receiving opening. Since the bistable coupling ring of the faceplate directly engages the film of the pouch about the stoma-receiving opening, the pouch component does not require a semi-rigid ring or flange which could prevent the pouch from being easily disposable in a toilet bowl or water closet. Furthermore, the bistable coupling ring of the present invention provides a fluid tight seal and latching interconnection with the pouch, thereby protecting exterior water soluble layers of the pouch from contact with body fluids which may flow through the pouch's stoma-receiving opening. The present invention provides a faceplate for a two-piece collection system comprising a thin, flexible adhesive pad for adhesive attachment to a skin surface, a coupling ring formed of flexible, semi-rigid polymeric material, and attachment means for joining the coupling ring to the flexible pad. The coupling ring has an annular base defining a central opening and a contact face thereon surrounding said opening. An annular collar extends from the base adjacent to and concentric with said opening. A bistable annular latching member is joined to the collar along an annular hinge line, said latching member providing a contact surface and being pivotable about the hinge line between a stable, substantially untensioned first state wherein the latching member projects generally axially away from the collar and a stable, tensioned second state wherein the latching member extends reversely towards the base with the contact surface of said latching member positioned for tight engagement with the base's contact face. When the latching member is in its first state, the coupling ring may be inserted into the opening of the pouch component and, thereafter, the latching member can be shifted to its second state so that the pouch component is clamped between the contact surface of the latching member and the contact face of the base. In such second state, the latching member forcefully engages the interior of the pouch component so as to produce a fluid-tight interlock between the parts. Therefore, the pouch component does not require a coupling ring or flange which could interfere with effective disposal of the pouch, and the coupling ring engages the interior of the pouch component so as to shield the exterior layers of the pouch component which may be water soluble. Other features, advantages, and objects will become apparent from the specification and drawings of a preferred embodiment of the present invention. Figure 1 is a perspective view of a two-piece ostomy appliance embodying this invention, the appliance being shown with the pouch component uncoupled from the faceplate component for clarity of illustration. Figure 2 is a schematic vertical sectional view of the faceplate component and the pouch component in separated condition. Figure 3 is a schematic vertical sectional view of the faceplate component after the coupling ring has been inserted into the opening of the pouch component but with the coupling ring in its first untensioned stable state. Figure 4 is a schematic vertical sectional view illustrating the two-piece appliance with the latching member in its tensioned inverted state such that it engages the periphery of the opening in the pouch component. Figures 5 - 7 are schematic vertical sectional views of the coupling ring illustrating the first and second stable states of the latching member as well as an unstable intermediate or transitional state of that member. In Figure 1, the numeral 10 generally designates a two-piece ostomy appliance comprising a pouch component 11 and a faceplate component 12. Except as described below, the faceplate component 12 may be of known construction and, in the embodiment illustrated, comprises a flexible panel 13 composed of an inner ring 13a of thermoplastic film and an outer patch or ring 13b of microporous material or other suitable sheet material. The microporous patch 13b is provided with a coating of pressure sensitive adhesive 14 along one surface for peristomal attachment to a patient. The film ring 13a may be backed by a layer 13c of soft, pliant, moisture-absorbing adhesive material commonly known in the medical field as protective skin barrier material. The faceplate component 12 has a stoma-receiving opening 15 which may be reformed or enlarged by cutting prior to application so as to conform generally with the size and shape of the patient's stoma. As shown in Figure 2, a thin, flexible annular web 16 extends from the panel 13 from a heat sealed connection 17. The web 16 allows a patient to insert his/her fingers behind the coupling ring so that the user may more easily attach the coupling ring to the pouch component 11 and avoid exerting axial forces against the peristomal area which may be sensitive after surgery. For further details on the use of an annular web to give the faceplate coupling ring 20 a "floating" action, reference may be had to co-owned US-A-4,419,100. Although such a "floating" construction is preferred because of the advantages described, it will be understood that, if desired, the web may be omitted and coupling ring 20 may be joined directly to panel 13. The outer margin of web 16 is heat sealed at 16a to coupling ring 20. Coupling ring 20 includes an annular base 21 having a contact face 22 and an annular collar 23 extending from the base. The base 21 defines a central opening 24 with which the collar 23 is concentric and adjacent. A bistable annular latching member 25 is joined to the collar 23 along an annular hinge line 28 shown in Figure 3. The latching member 25 has a contact surface 25a on a side opposite from opening 24. The base portion 21, collar 23, and latching member 25 may be integrally formed of a low density polyethlene or any other suitable polymeric material having similar properties of toughness, stiffness and limited flexibility. As shown in Figures 2 and 3, the pouch component 11 has an annular opening 30 and a peripheral area or edge portion 32 extending about that opening. The pouch component 11 is comprised of a front panel 34 and a rear panel 35 joined along their margins by heat seal 36. The front and rear panels each include an exterior layer 37 and an interior layer 38. An additional tissue layer 39 may extend over the exterior layer 34 to provide softness and promote patient comfort. Exterior layer 37 is typically made of a water soluble polymeric material which is relatively strong and tough in a dry state such as, for example, polyvinyl alcohol or polyethylene oxide. In contrast, the interior layer 38 is comprised of a water insoluble material which, because of its composition or its relative thinness, is weak and depends on the soluble layer for support and structural integrity. Upon dissolution of the soluble layer, the inner insoluble layer readily collapses or disintegrates. Suitable materials for the inner layer 38 are polyvinylidene chloride or atactic polypropylene nitrocellulose, although any of a variety of other insoluble materials may be used. The tissue layer 39 may be made of a water soluble tissue or other fabric which will easily dissolve so as to be flushable in a toilet bowl or water closet. A thin, flexible gripping ring 40 may be connected along its inner edge portion 40a to the annular area 32 of the pouch component so that a user may grasp the ring 40 during connection to or removal from faceplate component 12. Like outer layer 37 of the pouch, the gripping ring 40 may, if desired, be formed of a tough, flexible, but water soluble polymeric material. Thus, when discarded into a flush toilet, ring 40 and outer layers 37 dissolve and layers 38 and 39 disintegrate, resulting in a pouch that is totally disposable and "flushable." It is to be understood, however, that while this invention is particularly useful with flushable pouches, the pouch 10 may be formed, if desired, of conventional non-soluble and non-disintegrating film materials. A characteristic feature of the coupling ring 20 is that its latching member 25 is bistable -- that is, the member is predisposed to assume in spring-like fashion either of the two stable conditions or states depicted in Figures 3 and 4. In its normal, untensioned state as shown in Figures 3 and 5, latching member 25 projects generally axially away from the base 21 and is substantially untensioned. The second stable state of the coupling ring 20 and latching member 25 is illustrated in Figures 4 and 7. In its second state, the latching member 25 is tensioned and extends reversely towards the base with the contact surface 25a of the latching member 25 positioned for tight engagement with the base's contact face 22 (see Figure 7). Figures 5-7 illustrate the operation of the coupling ring 20 and its bistable latching member 25. In the latching member's stable first state (Figure 5), the free end of latching member 25 defines an opening having a diameter d1. In the latching member's stable second state (Figure 7), the free end has a diameter d2 which is slightly greater than the diameter d1 of the first state because the latching member is under tension, its rearward pivotal movement being limited by contact face 22 of base 21. Between its two stable states or positions, the latching member has intermediate positions (Figure 6) where it is structurally unstable and under tension. When the latching member is in an intermediate position, its diameter d3 is greater than either diameter d1 or d2 of the first and second states. The circumferential stretching off the member in such intermediate positions produces hoop stresses or tensions that urge the latching member 25 to flip in springlike fashion towards either the stable first position (Figure 5) or the stable but tensioned second position (Figure 7). The length of the latching member 25 (measured between hinge 28 and the member's free end) should exceed the length of the collar 23 so that the contact surface 27 will reach and engage the contact face 22 in the latching member's second state. In use, as shown in Figures 3 and 4, the coupling ring 20 is inserted into the opening 30 in the pouch 11 so that the peripheral area or annular edge portion 32 of the pouch extends about collar 23. It should be noted that the free end of the latching member 25 has a diameter substantially equal to or greater than the diameter of the opening 30 in the pouch component 11. However, even if the diameter of the free end is greater than the diameter of the opening 30, the deformable coupling ring 20 may still be easily inserted into the opening 30 by first urging an arcuate portion of the member's free end into the opening and then slightly deforming the latching member so that the remainder of the periphery may be popped into opening 30. To facilitate this connection, the user may grasp the annular gripping ring 40 to manipulate the coupling ring 20 into the opening 30. Once the annular edge portion 32 of the pouch is fitted about collar 23, the latching member 25 can be pivoted in an axial direction towards the base 21 to clamp the annular periphery or edge portion of the pouch between contact face 22 of the base 21 and surface 25a of the latching member (Figure 4). With latching member in its second stable state, the coupling ring 20 provides a fluid-tight latching interconnection between the pouch component 11 and the faceplate component 12. This relationship is especially advantageous because the contact surface 25a sealingly engages the water-insoluble interior layer 38 of the pouch component 11, thereby shielding and protecting the water soluble exterior layer 34 (also ring 40) from fluids flowing through the opening 30 or contained in the pouch 11. While in the foregoing, I have disclosed an embodiment of the invention in considerable detail for purposes of illustration, it will be understood by those skilled in the art that many of these details may be varied without departing from the scope of the invention as defined in the appended claims.

Claims: A faceplate for a two-piece collection system comprising a thin, flexible adhesive panel (13) for adhesive attachment to a skin surface; a coupling ring (20) formed of flexible, semi-rigid polymeric material; attachments for joining said coupling ring (20) to said panel (13); said coupling ring having an annular base (21) defining a central opening (24), an annular collar (23) extending from said base adjacent to and concentric with said opening, and an annular latching member (25) joined to said collar and providing a contact surface (25a); characterised in that said coupling ring (20) has a contact face (22) surrounding said opening (24) and facing generally axially away from said panel (13); said latching member (25) is bistable and is joined to said collar (23) along an annular hinge line (28) for pivotal movement between a stable, substantially untensioned first state wherein said latching member projects generally axially away from both said collar (23) and said contact face (22) and a stable, tensioned second state wherein said latching member extends reversly towards said base (21) with said contact surface (25a) of said latching member positioned for tight engagement with said base's contact face (22). The faceplate of claim 1 in which said coupling ring (20) is formed integrally of said flexible, semi-rigid polymeric material. The face plate of claim 1 or 2, in which said latching member (25) includes a free end portion; said free end portion, when said member is in said second state, being under hoop stress and having an outside diameter greater than when said member is in untensioned first state. The face plate of claim 3 in which said latching member (25) passes through intermediate states as it is shifted between said first and second states, said free end portion having an outside diameter in said tensioned second state smaller than said outside diameter of said free end portion in said intermediate states. The face plate of any one of claims 1 to 4, in which said attachment means comprises a thin, flexible annular web (16) having an inner edge secured to said panel (13) and a concentric outer edge secured to said base (21) of said coupling ring (20). A two-piece collection system comprises a pouch component (11) and a face plate component (12); said pouch component (11) having a wall (34) defining a stoma-receiving opening (30); said faceplate component (12) comprising a thin, flexible adhesive panel (13) for adhesive attachment to a skin surface, a coupling ring (20) formed of flexible, semi-rigid polymeric material, and attachment means (16) for joining said coupling ring to said panel; said coupling ring (20) having a base (21) defining a central opening (24); an annular collar (23) extending from said base adjacent to an dconcentric with said opening (24) and an annular latching member (25) joined to said collar (23) and providing a contact surface (25a); characterised in that said coupling ring (20) has a contact face (22) surrounding said opening (24) and facing generally axially away from said panel (13); said latching member (25) is bistable and is joined to said collar (23) along an annular hinge line (28) for pivotal movement between a stable, substantially untensioned first state wherein said latching member projects generally axially away from both said collar (23) and said contact face (22) and a stable, tensioned second state wherein said latching member extends reversly towards said base (21) with said contact surface (25a) of said latching member positioned for tight engagement with said base's contact face (22). The two-piece collection system of claim 6 in which said coupling ring (20) is integrally formed of said flexible, semi-rigid polymeric material. The two-piece collection system of claim 6 or 7, in which said latching member (25) includes a free end portion; said free end portion, when said latching member is in its second state, being under hoop stress and having an outside diameter greater than when said latching member is in said untensioned first state. The two-piece collection system of claim 8, in which said latching member (25) passes through intermediate states as it is shifted between said first and second states, said free end portion having an outside diameter in said tensioned state smaller than the outside diameter of said free end portion in said intermediate states. The two-piece collection system of any one of claims 6 to 9, in which said attachment means (16) comprises a thin, flexible annular web having an inner edge secured to said panel and a concentric outer edge secured to said base (21) of said coupling ring (20). The two-piece collection system of any one of claims 6 to 10, in which said pouch component (11) includes a flexible annular gripping ring (40) having an inner edge portion externally secured to a peripheral area of said wall (34) of said pouch component about said stoma receiving opening (30). The two-piece collection system of any one of claims 6 to 11, in which said wall (34) of said pouch component (11) is comprised of a relatively thin and weak water-insoluble interior layer (38) and a relatively strong but water-soluble exterior layer (37). The two-piece collection system of claim 12, in which said water-soluble exterior layer (37) has an exposed edge at said stoma receiving opening (30); said base (21), collar (23) and latching member (25) of said coupling ring (20) shielding said edge from contact with fluids passing through said latching member, collar, and base when said components are coupled together. The two-piece collection system of any one of claims 11 to 13, in which said gripping ring (40) is formed of a water-soluble polymeric material.

Inventors: METZ MICHAEL, METZ, MICHAEL
Applicants: HOLLISTER INC, HOLLISTER INCORPORATED
Application year: 1994
Main classification: A61F5
IPC codes: A61F5